scholarly journals Optimization of Low-Cost Ti-35421 Titanium Alloy: Phase Transformation, Bimodal Microstructure, and Combinatorial Mechanical Properties

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2791 ◽  
Author(s):  
Fuwen Chen ◽  
Guanglong Xu ◽  
Yuwen Cui ◽  
Hui Chang
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Phase Transformation ◽  
Phase Transformations ◽  
Kinetic Modeling ◽  
Raw Materials ◽  
Low Cost ◽  
Aged Alloy ◽  
Bimodal Microstructure ◽  
Comparable Performance

A sophisticated understanding of phase transformations and microstructure evolution is crucial in mechanical property optimization for the newly developed low-cost Ti-35421 (Ti-3Al-5Mo-4Cr-2Zr-1Fe wt.%) titanium alloy. The phase transformations in dual-phase Ti-35421 were studied by experiments and thermo-kinetic modeling. The phase transformation reactions and temperature ranges were determined as β→αlamellar [410–660 °C], αlamellar→β [660–740 °C], αlath→β [740–825 °C]. The Gibbs-Thomson effect and multicomponent diffusivities were proven to be responsible for the distinguishing behaviors of growth and dissolution between two α phases. The aging temperature of 540 °C was optimized based on calculations. It introduced a bimodal microstructure containing stubby α lamellae and β matrix. The mechanical properties of bimodal Ti-35421 were tested and compared with baseline alloy Ti-B19 and other near-β titanium alloys. The 540 °C aged alloy exhibits an optimal combination of mechanical properties with tensile strength of 1313 MPa, yield strength of 1240 MPa, elongation of 8.62%, and fracture toughness of 75.8 MPa·m1/2. The bimodal Ti-35421 shows comparable performance to Ti-B19 but has lower cost in raw materials and processing. The results also demonstrate that thermo-kinetic modeling can effectively be utilized in tailoring microstructure and enhancing mechanical properties.

scholarly journals A Review on Diffusion Bonding between Titanium Alloys and Stainless Steels

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
De-feng Mo ◽  
Ting-feng Song ◽  
Yong-jian Fang ◽  
Xiao-song Jiang ◽  
Charles Q. Luo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Titanium Alloy ◽  
Titanium Alloys ◽  
Stainless Steels ◽  
Diffusion Bonding ◽  
Low Cost ◽  
Phase Interface ◽  
Intermetallic Phases ◽  
Voids Growth

High-quality joints between titanium alloys and stainless steels have found applications for nuclear, petrochemical, cryogenic, and aerospace industries due to their relatively low cost, lightweight, high corrosion resistance, and appreciable mechanical properties. This article reviews diffusion bonding between titanium alloys and stainless steels with or without interlayers. For diffusion bonding of a titanium alloy and a stainless steel without an interlayer, the optimized temperature is in the range of 800–950°C for a period of 60–120 min. Sound joint can be obtained, but brittle FeTi and Fe-Cr-Ti phases are formed at the interface. The development process of a joint mainly includes three steps: matching surface closure, growth of brittle intermetallic compounds, and formation of the Kirkendall voids. Growth kinetics of interfacial phases needs further clarification in terms of growth velocity of the reacting layer, moving speed of the phase interface, and the order for a new phase appears. The influence of Cu, Ni (or nickel alloy), and Ag interlayers on the microstructures and mechanical properties of the joints is systematically summarized. The content of FeTi and Fe-Cr-Ti phases at the interface can be declined significantly by the addition of an interlayer. Application of multi-interlayer well prevents the formation of intermetallic phases by forming solid solution at the interface, and parameters can be predicted by using a parabolic diffusion law. The selection of multi-interlayer was done based on two principles: no formation of brittle intermetallic phases and transitional physical properties between titanium alloy and stainless steel.

scholarly journals Feasibility study of a novel hot stamping process for Ti6Al4V alloy

2018 ◽  
Vol 190 ◽  
pp. 08001
Author(s):  
Mateusz Kopec ◽  
Kehuan Wang ◽  
Yaoqi Wang ◽  
Liliang Wang ◽  
Jianguo Lin
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Phase Transformation ◽  
New Technology ◽  
Hot Stamping ◽  
Constant Strain Rate ◽  
Tensile Tests ◽  
Ti6al4v Titanium Alloy ◽  
Stamping Process ◽  
Forming Tools

To investigate the feasibility of a novel hot stamping process for the Ti6Al4V titanium alloy using low temperature forming tools, mechanical properties of the material were studied using hot tensile tests at a temperature range of 600 - 900°C with a constant strain rate of 1s-1. Hot stamping tests were carried out to verify the feasibility of this technology and identify the forming window for the material. Results show that when the deformation temperature was lower than 700°C, the amount of elongation was less than 20%, and it also had little change with the temperature. However, when the temperature was higher than 700°C, a good ductility of the material can be achieved. During the forming tests, parts failed at lower temperatures (600°C) due to the limited formability and also failed at higher temperatures (950°C) due to the phase transformation. The post-form hardness firstly decreased with the temperature increasing due to recovery and then increased due to the phase transformation. Qualified parts were formed successfully between temperatures of 750 - 850°C, which indicates that this new technology has a great potential in forming titanium alloys sheet components.

scholarly journals 3D Printing of Continuous Fiber Reinforced Low Melting Point Alloy Matrix Composites: Mechanical Properties and Microstructures

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3463
Author(s):  
Xin Wang ◽  
Xiaoyong Tian ◽  
Lixian Yin ◽  
Dichen Li
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Matrix Composite ◽  
Raw Materials ◽  
Low Cost ◽  
Metallic Matrix ◽  
Interfacial Microstructure ◽  
Fiber Reinforced ◽  
Continuous Fiber ◽  
Alloy Matrix

A novel 3D printing route to fabricate continuous fiber reinforced metal matrix composite (CFRMMC) is proposed in this paper. It is distinguished from the 3D printing process of polymer matrix composite that utilizes the pressure inside the nozzle to combine the matrix with the fiber. This process combines the metallic matrix with the continuous fiber by utilizing the wetting and wicking performances of raw materials to form the compact internal structures and proper fiber-matrix interfaces. CF/Pb50Sn50 composites were printed with the Pb50Sn50 alloy wire and modified continuous carbon fiber. The mechanical properties of the composite specimens were studied, and the ultimate tensile strength reached 236.7 MPa, which was 7.1 times that of Pb50Sn50 alloy. The fracture and interfacial microstructure were investigated and analyzed. The relationships between mechanical properties and interfacial reactions were discussed. With the optimized process parameters, several composites parts were printed to demonstrate the advantages of low cost, short fabrication period and flexibility in fabrication of complex structures.

CHLOROHYDRINATION OF NR LATEX BY USING SODIUM HYPOCHLORITE FOR FUEL-RESISTANT MATERIALS

2016 ◽  
Vol 89 (2) ◽  
pp. 251-261 ◽  
Author(s):  
T. Chanroj ◽  
P. Paoprasert
Keyword(s):  
Mechanical Properties ◽  
Sodium Hypochlorite ◽  
Surfactant Concentration ◽  
Raw Materials ◽  
Low Cost ◽  
Scaling Up ◽  
Hydrochloric Acid Concentration ◽  
Thermal And Mechanical Properties ◽  
Simple Method ◽  
Production Processes

ABSTRACT NR is hydrophobic and cannot be used to store, transfer, or make contact with hydrocarbon compounds. We report a simple method to increase the hydrophilicity of NR: a chlorohydrination reaction of NR latex by using sodium hypochlorite is described. It was found that only chlorohydrinated NR was obtained and side products were unnoticeable. The effects of sodium hypochlorite concentration, hydrochloric acid concentration, surfactant concentration, and reaction time on chlorohydrin content in NR were investigated. The swelling resistance of chlorohydrinated NR with 11% chlorohydrin content in diesel and gasohol fuels was improved nearly 3-fold and 4-fold, respectively, compared to that of the unmodified NR. The thermal and mechanical properties of the chlorohydrinated NR were characterized and found to be similar to those of pristine NR, indicating that the chlorohydrinated NR can be an excellent substitute for NR. This method has merits such as low cost of raw materials, easier and greener production processes than traditional methods, and scaling-up possibilities for the fabrication of chlorohydrinated NR for a variety of applications.

Absorbable Suture Made from Rice Starch

2010 ◽  
Vol 123-125 ◽  
pp. 291-294 ◽  
Author(s):  
Sittiporn Punyanitya ◽  
Rungsarit Koonawoot ◽  
Sakdiphon Thiensem ◽  
Surasit Laosatirawong ◽  
Anirut Raksujarit
Keyword(s):  
Mechanical Properties ◽  
Polymer Films ◽  
Raw Materials ◽  
Low Cost ◽  
High Water ◽  
Hot Water ◽  
Rice Starch ◽  
Absorbable Suture ◽  
Milling Method ◽  
Simple Technology

The main objective of this work is to make an absorbable monofilament suture from Thai rice starch. The improvement of the mechanical properties of Thai rice starch polymer films were achieved by addition of small amount of gelatin, carboxymethylcellulose (CMC) and carbon nanopowders. The carbon nanopowders were produced from coconut shell in our laboratory room by milling method. The incorporation of carbon nanopowders with a high aspect ratio and/or an extremely large surface area into Thai rice starch polymer films improves their mechanical performances significantly. Additionally, the black color from carbon nanopowder is easily visualized in tissue during surgery. The manufacturing processes are very simple by blending of the raw materials in hot water and then dry heating in electric oven. The final product was characterized of microstructures and mechanical properties. The resulting Thai rice starch-carbon nanocomposites possess several advantages for manufacture of sutures: 1. high water resistance that can be uses in the human body. 2. high mechanical strength that appropriate to manufacture of sutures. 3. biocompatibility and bioabsorbable. 4. low cost. 5. Eco-friendly green nanocomposites. However, the method of size designation of sutures fibers and needle attachment are the problem which restricts our suture in really applications. The investigation of knowledge and simple technology of manufacture of suture and needle attachment will be performed.

Physical and mechanical properties of polyurethane thermoset matrices reinforced with green coconut fibres

2020 ◽  
Vol 54 (30) ◽  
pp. 4841-4852 ◽  
Author(s):  
Douglas Lamounier Faria ◽  
Laércio Mesquita Júnior ◽  
Ana Angélica Resende ◽  
Daiane Erika Lopes ◽  
Lourival Marin Mendes ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bulk Density ◽  
Raw Materials ◽  
Chemical Constituents ◽  
Low Cost ◽  
Physical And Mechanical Properties ◽  
Tensile Tests ◽  
Sem Images ◽  
The Matrix ◽  
Coconut Fibre

Currently, the use of composites to replace parts made only with plastics has been gradually employed. The advantages of these composites are low cost, high availability of raw materials and good physical and mechanical properties. Thus, this work aimed at producing and characterizing composites produced with coconut fibre reinforced polyurethane matrices. The coconut fibres were studied as to their chemical constituents, aspect ratio, bulk density, pH, tensile properties, and surface SEM images. The composites were prepared using the hand lay-up process and four different concentrations of coconut fibre were evaluated: 30, 40, 50, and 60%. The composites were assessed as for water absorption after 20 days of immersion, bulk density, impact IZOD, tensile tests, and visualize the matrix-reinforcement interface using SEM. The electron micrographs showed a great deal of impurities on the surface of coconut fibres, such as greases, waxes, and gums, due to the high amount of extraction material (19.78%), which damages the adherence of the polymer onto the coconut fibre and, as observed, cause detachment between the reinforcement and the matrix. The tensile strength of the composites tended to increase as greater amounts of coconut fibres were added to the matrix. The averages were around 6.51 to 6.72 MPa for composites with 30 and 60% fibres, respectively. Therefore, coconut fibres can be considered as an alternative to synthetic fibres commonly used in composites, and they can be used at a ratio of 60% without prejudicing the properties of the composites, making them lighter and cheaper.

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